This invention relates generally to safety equipment, namely, derails, which are commonly used for derailing railed vehicles, particularly powered and non-powered railroad cars such as box cars, flat bed railroad cars and the like, which are undesirably moving along railroad tracks. More specifically, the invention relates to hinged derails which may be selectively positioned adjacent one of a pair of railroad tracks for movement between an operating position for engaging and derailing a wheel of an undesirably moving railroad car and an inoperative position for allowing a moving railroad car to pass by the derail without undesirably engaging and derailing the moving railroad car. This invention also relates to a method for constructing the hinged derail of the invention.
Derails of various types have been used for many years in the railroad industry, some derails being in excess of one hundred years old. Derails are commonly used as safety devices to prevent or limit unintended or undesired movement of a railroad car, such as a box car. Derails have been used extensively, such as along side rails adjacent to a main line track for railroad trains and in railroad yards where railroad cars are constantly being moved, such as between coupled positions and uncoupled positions. Typical derails are configured to be manually or automatically moveable between a retracted or inoperative position in which a deflecting block is disposed adjacent but away from a rail for allowing free movement of a railroad car past the derail and alternatively, at a deployed or operative position in which the deflecting block is positioned on top of and aligned with one of a conventional pair of railroad rails for engaging and deflecting an oncoming wheel of an undesirably moving railroad car off the track or pair of rails. These derails cause the one wheel to be deflected and thereby the car to be deflected to a stopped, non-moving position so as to avoid injury to other equipment or to personnel.
Generally speaking, hinged derails include a deflecting block rigidly mounted on a derail shoe. The derail shoe is pivotal about a pivot axis, mounted on a base secured to a pair of railroad ties adjacent one of a pair of rails. Examples of such hinged derails may be seen, for example, in Hayes U.S. Pat. No. 988,190; Hayes U.S. Pat. No. 1,464,607; Hayes U.S. Pat. No. 1,627,092; Hayes U.S. Pat. No. 1,702,083; Hayes U.S. Pat. No. 2,430,567; Hayes U.S. Pat. No. 3,517,186; and Pease U.S. Pat. No. 6,178,893 B1.
In the operation of hinged derails, a derail shoe is pivoted between the retracted or inoperative position, which is spaced away from the railroad rail, and a deployed position or operative position where the deflecting block of the derail shoe is aligned generally on top of a rail. Proper alignment requires both lateral alignment and vertical alignment to a location on top of the rail with the deflecting block positioned to engage the leading wheel of an undesirably moving railroad car. The base of the derail is generally affixed to a pair of railroad ties of the type commonly used in the railroad industry, with attachment being accomplished generally by spikes driven through openings in the base into the ties. The base is mounted on the ties, in the area between a pair of rails and in a position operatively adjacent to one of the rails.
Once the derail is in position, that is, affixed to the railroad ties, the installed derail is in a substantially permanent position. The derails are made of solid steel and are very heavy as they must derail a heavy, moving rail car. The pivoted derail shoe itself may weigh in the range of 80-120 pounds. A double ended derail, to be described, is heavier and has a weight of up to about 120 pounds while a single ended derail is closer to the lower end of the range. Clearly, any of the heavy derail shoes are not easily manually rotated between operative and inoperative positions. In the inoperative position, the derail shoe, being pivotally mounted to the derail base, is deployed away from the adjacent rail in a substantially aligned position on the base in a position with the derail block facing downwardly and away from the rail so as to allow a moving railroad car to pass without being derailed. When desired, the railroad worker must manually lift the pivoted derail shoe in an upward circular motion and then rotate it downwardly into position with the deflecting block on top of the rail so the deflecting block will be in a position for engaging the wheel of a railroad car which is moving in an undesired manner. This means that the railroad worker must physically bend down and manually and rotatably lift the derail shoe about the pivot axis of the attachment to the base and move the derail shoe to the operative position on the rail. This action is physically difficult and can cause physical injury, such as to the back of the railroad worker. Similarly, when the derail shoe with the deflecting block is moved by the worker in the opposite direction, that is, from the deflecting or operative position to the inoperative position, the same problem occurs, that is the heavy derail shoe must be lifted and rotated in the opposite direction to the inoperative position. Again, the operator risks or may even encounter serious injury such as to the back.
Thus, there is a clear need for a hinged derail that significantly reduces the stress placed on an operator's back in rotationally moving the derail shoe both from the inoperative position to the operative position on the rail and from the operative position to the inoperative position. In addition, there is a need to provide forcible lifting assistance to the required manual lifting of the derail shoe without using expensive parts, and without adding weight to the already heavy derail shoe. Finally, there is a need to provide a method for constructing the hinged derail of this invention in an efficient and economical manner.